Storage vessel



Sept. 16, 1958 Filed Feb. l, 195s STORAGE VESSEL Q Y!" o 2 sheets-sheet 1 INVENTok. Ezwzn @Daar-Inger BY hmqwb AT TORNEYS.

Sept. 16, 1958 G. DUERINGER 2,852,110

s'ToRAGE VESSEL 'l Filed Feb. 19. 1953' y 2 sheets-sheet 2 n u u n e u o n a n e a INVENTQR.

Erwm G.Dz.zerzrzger AT TORNEYS.

In l FIG. 7.

Iconoloannoooovno Unite States 2,852,110 s TorzAoE vEssnL G. Dueringer, -Milwaukee, Wis., assiguor to A. 0. Smith Corporation,-Milwaukee,:Wis., a corporation of New York ApplicationtFebrnaryh, 1(953, vSetrial`No. 337,101 1.Claim. (Cl. '189113) -ly reduces `the number of parts-to be handled during shipment and erection of the silo.

Another object lis to provide a strong supporting foundation for the silo whereby the foundation may be conveniently constructed-by the former rwith a minimum of concrete. A i y Y' `v In general the silo of the presentinvention comprises a generallycylindrical body section which is enclosed at the top byagenerally 'curved roof and is supported at the bottom by a concrete foundation. vThe body section consists ofra pluralityrof glass-coated steel sheets or strips which are successively wound 11i-helical or spiral form. The trailing end of each strip is secured along a vertical line to the leading end of the following strip.

The helical-or side vedges of -the strips are overlapped and secured together withthe upper side edge of` each lower vconvolutionloverlapping lthe -lower side edge of the preceding upper convolution to provide aninterior surface invwhich Aeach lower convolution is outwardly oset so as .not toobstruct the downward Ymovement of-the contained material. Each-.ofthe sheets isy constructed with a predetermined thickness to withstandthe internal Ypressure `of the-stored material'at the level at which the sheet is disposed.

In addition the silozisiprovidedlwith aA suitable internal supporting structure which carries acrotatingcutter arm to undercut the silage and a conveyor unit to transport the cut silage to the exterior of the silo. 1" he silo is also provided with a suitabledoor or manway which registers with the conveyor unit toeifect the removal of the contained material.

In the drawings:

Figurevl is a perspective view ofV a completed silo;

Fig. 2 is an enlarged fragmentary. perspective view of the silo with parts broken awayto show the internal Ysupporting structure;

Fig. 3 is a fragmentary vertical section of the silo showing the position of the mechanical unloading apparatus;

Fig. 4 is a` horizontal section taken along line 4-4 of Fig. 3; l

Fig. 5 is a fragmentary transverse section taken along line 5 5 of Fig. #tandV showing the unloading trough;

Fig. 6 is a plan view of aA sheet with parts broken away andshowinghow the taperedend portionsof the upperatent Z,852,l l0 Patented lSept. 1 6, v1958 most and lowermost strip are lformedtfrorn `4a single strip;and

Fig. 7 is a plan View of one of ,theintermediatestrips with a part lbroken away.

Referring to the drawings there .is shown la generally cylindrical'silo 1 or the like which is -enclosed at'thetop by a generally conical roof `2`and supported patthe yfoottom by an annular concrete footing 3.

Silo 1 consists of a plurality of strips 44er `sheets of metal which are successively woundv inahelicalfmanner. Strips 4 are preferably constructed of steel coated with glass, plastic or a similar corrosion resistant materialor they may be made of a suitable corrosion.resistantfalloyi The strips are each ,constructedtwith "a predetermined thickness to withstand 'the internal lp'r'es'sur'euof thev :contained material at the particular position where each strip isloca'ted. For example, inasilo Ihaving'a diameter of about twenty feet, theuppermost of the v stripsfr4 `is the longest of the lfour strips andi's constructed with a thickness in the neighborhood of one-sixteenth of 'an inch. The following or intermediate strip hasa slightly greater thickness, approximately three thirty-seconds of an inch, and the intermediate strtipfis followed iriturn by the grade strip .which has the greatestthickness ofthe four strips,'such as one-eighth ofw'an inch.l As the grade strip extends downwardly to slightlybelow gradev levelit is subjected to an internal pressure exertedbythe entire weight of the contained material, and to-withstand this pressure'the grade strip is designed with agrea'terthickness than the other strips.

The lowermost of strips 4 is attached to the grade strip and extends downwardly therefrom in a helical n'ian'rier to footing 3. As `the lowermost strip is `not subjected to the pressure of the contained material,V as will befhereinvafter shown, it is designed with a minimum thickness approximating the thickness of the uppermost strip; namely, about one-sixteenth of an inch.

In order that the circular lower edge of silo 1 lies in a horizontal piane an-d that the silol be vertically disposed when resting on footing 3, the trailing end of theiloWrmost of the strips 4 is tapered to a poin'tflike tipfasindicated by 5. 'i

Similarly the leading end of the uppermost of the strips 4 is tapered to a pointed tip 6 s o that the upper-'circular edge ofv silo 1 also li'esin' a substantially horizontal plane. Fig. 6 shows how the uppermost-'strip andthe lowermost stripvrnay be cut from a single longstripftO give the properly tapered tips 5 and 6.y

As there shown -the trailingfaiidleading, ends ofgeach Vof the strips -4, with the exception of vthe aforementioned trailing end of the lowermost 'strip and the llea`,ding"`,e11d of the uppermost strip, are cut yon" the helixanglarto obtain a vertical joint when the trailing end of onestrip is secured in a lapping relationtothe ,leadingv end of the following strip. A plurality of spaced smoothrhead bolts 7 are employed to secure the lapped ends of ,strips 4 together. -The bolts are inserted 'from theinterior of the Ysilo through aligned holes inthe vertical lapped ends of the respective strips and are yengaged on the outsidetof the silo by suitablenilts.V

The strips 4 are wound in a helical manner from the top down with `the upper'side edge of each successive convolution overlapping the lower side edge of the preceding t convolution soy that each lower" 'convolution is offset outwardly to provide an internal silo surface which will not obstruct the downward movement off'silaige or similar contained material. l'

'To attach the overlapping helicalside edges of strips 4 together to form-the cylindrical'b'ody portion of the :silo a plurality ofgspaced smooth-head bolts v'8 'are inserted from the interior of silo 1 through suitable aligned holes in `the lapped side edgesv of'strips ll and arey engaged on the exterior of the silo by suitable nuts. The bolt holes in the overlapped portion of each strip adjacent the lower side edges thereof are uniformly spaced and equidistant in all strips.

However, the bolt holes in the overlapping portion of each strip, adjacent the upper side edge thereof, are not uniformly spaced, but instead are positioned in alignvment with the holes adjacent the lower side edges of the preceding convolution and thus the spacing of holes adjacent the upper side edges of strips 4 must compensate for the overlap of convolutions and the varying thicknesses of the strips.

To prevent leakage of silage juices or the like through the vertical or helical joints, a mastic or other sealing material may be disposed between the lapped edges prior to the securement thereof by the bolts 7 and 8.

Roof 2 is formed of a number of pie-shaped segments with ilange extremities to provide an annular ange that extends over the top circular edge of silo 1 and which is secured thereto. A suitable opening is provided in roof 2 through which the silage or the like is introduced into the silo. To maintain the air-tight properties of the silo the opening is closed by a removable cover 9 when not in use.

Footing 3, as seen in Fig. 2, which supports silo 1 is generally annular in shape and is constructed of concrete or the like. Footing 3 is disposed beneath the exterior grade level of the structure with the distance beneath grade level depending on the frost penetration in the particular area where the structure is to be erected.

A base angle ring 10 rests on footing 3 and is secured by suitable bolts to the inner bottom edge of silo 1. Ring 10 may be constructed of a number of arcuate segments which are individually bolted to the silo. A plurality of circularly spaced anchor bolts 11 are embedded in footing 3 and project upwardly therefrom.

A clamp plate 12 cooperates with each bolt 11 to attach base angle ring 10 to the footing 3. The outer extremity of each clamp 12 rests on the horizontal flange of angle ring 10 and the upwardly projecting end of the corresponding bolt 11 extends through an opening in the clamp 12 and is engaged by a suitable nut to secure the angle ring 10 to the footing 3. To maintain each clamp 12 in a substantially horizontal position and insure uniform pressure on angle ring 10, each clamp is provided with a downwardly bent inner end which rests on footing 3.

A generally cylindrical skirt ring 13 is concentric with and inwardly spaced from the cylindrical wall of silo 1 and rests on footing 3. Ring 13 extends upwardly from footing 3 to the interior grade level of the structure which is a slight distance above the exterior grade level.

Ring 13 is formed of a plurality of arcuate skirt sections 14. Each skirt section 14 is provided with a pair of vertical side flanges 15 and an inwardly extending top 'l' flange 16. Suitable bolts are employed to attach the side anges 15 of adjacent skirt sections together toform theY cylindrical skirt ring 13.

Skirt ring 13 is utilized to support an annular plate 17 which serves as a track for the outer extremity of a rotating cutter arm. The outer circular edge of plate or track 17 is secured by means of an angle ring 18 to the inner surface of silo 1, and the inner circular edge of track 17 is secured to the upper flange 16 of skirt sections 14. Track 17 is provided with suitable openings 19 or poke holes through which concrete may be poured into the annular space between the silo 1 and skirt ring 13 as a inal step in the erection of the structure. To facilitate shipment and handling the track 17 may consist of a plurality of arcuate segments. To provide a trough wherein the cut silage may be conveyed to the exterior of the silo a pair of spaced parallel channel members 20 extend diametrically across silo 1 and are secured at the ends thereof to the underside of track 17. The skirt'sections 14 adjacent the channels 2i) Cil are reduced in height to permit the channels to extend outwardly of ring 13 and be secured to the underside of the track 17.

A generally semi-circular anged plate 21 connects the spaced channels at the center of silo 1. Channels 20 and plate 21 carry a at trough plate 22 which extends outwardly from the center of the silo in the direction of the open side of plate 21 to the skirt ring 13. Plate 22 is secured to the lower ange of each of the channels 20, to the lower edge of plate 21 and to the upper flange 16 of the front reduced portion of skirt 13. A trough 23 is thereby defined by channels 20, plate 21 and plate 22.

The space between silo 1 and skirt ring 13 contains concrete 24 or the like which is poured through poke holes 19 in track 17. Concrete 24 takes the shape of an annular wall and serves to generally reinforce and strengthen the structure.

To remove the cut silage from the silo, the silo is provided with a manway or unloading opening 25 which registers with trough 23. Suitable channel members 26 are secured about the opening 25 to strengthen the same and provide a smooth-edged generally rectangular entry. A suitable cover, may be employed to close off opening 25 and maintain the air-tight properties of the structure when the silage is not being removed.

The mechanical cutting and unloading apparatus, shown schematically, used to cut and remove the silage from the structure may correspond to that disclosed in the co-pending application of Julius B. Tiedemann, Serial No. 98,794, now Patent No. 2,635,770, entitled, Method of Unloading Stored Material and Apparatus Therefor. The apparatus comprises a rotating cutter arm 27 with the outer end of the arm adapted to ride on track 17 to undercut and discharge the silage into trough 23 at the central portion of the silo. A conveyor unit 28 operating in trough 23 conveys the silage through opening 25 to the exterior ofthe silo.

The central area within silo 1 encircled by the skirt ring 13 is adapted to contain ground fill 29 and the fill provides additional support for the channels 20 and plate 22.

To protect all the metal parts of the structure, in addition to strips 4, against corrosion from either the elements or the material contained within the structure the metal parts may be given a protective enamel or plastic coating. p

The present silo with the use of the helical construction reduces the number of plates required to construct a silo, or storage vessel, of given dimensions. The use of fewer plates reduces the number of joints which results in a savings in sheet metal overlaps as well as a savings in bolts and mastic.

The ordinary metal silo is constructed from a number of rectangular steel plates which are individually squared, drilled, rolled to curvature and coated. Both in the eld and in the shop a large proportion of the total labor is spent in the transporting and the repeated handling of the multiple parts. The use of several helical strips, as shown in the present invention, in place of the large number of rectangular plates overcomes this ineiciency and brings about a definite saving in labor of manufacture and handling.

Although the invention has been described as applied to the use of enamel or glass coated metal strips it is contemplated that other materials such as plastic may be employed in which event the strips would be secured together by means other than bolting.

Various embodiments of the invention may be employed within the scope of the following claim.

I claim:

A cylindrical, vertically disposed silo-like storage vessel comprising a body section having a single supporting and containing wall, said wall being formed of a plurality of strips of material helically wound in a series of partially overlapping convolutions, securement means extending through the overlapping convolutions to secure the strips together, sealing material disposed between the overlapping convolutious of said strips to form a substantially airtight wall for the vessel, said strips being of predetermined varying thicknesses to withstand the vessel load and the internal pressure of the stored material at the particular position at which each strip is disposed in the body section, a roof member enclosing the top of said body section, and a foundation member disposed beneath the body section to support the same and close off the bottom of the section with the said metal strips being wound around at least a portion of the foundation to enclose said portion of the foundation and pro- References Cited in the tile of this patent UNITED STATES PATENTS 726,649 Craine Apr. 28, 1903 1,168,545 Nicholson Jan. 18, 1916 1,275,558 Holmgreen Aug. 13, 1918 2,592,559 Graham et al Apr. 15, 1952 2,635,770 Tiedemann Apr. 21, 1953 2,729,313 Ernestus Jan. 3, 1956 FOREIGN PATENTS 279,067 Switzerland Feb. 16, 1952 

